The disclosure relates generally to a wireless distribution system (WDS), and more particularly to identifying remote units in a WDS.
Wireless customers are increasingly demanding digital data services, such as streaming video and other multimedia contents, for example. Some wireless customers use their wireless devices in areas poorly serviced by conventional cellular networks, such as inside certain buildings or areas. One response to the intersection of these two concerns has been the use of WDSs, such as a distributed antenna system (DAS) as an example. A DAS can be particularly useful when deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive radio frequency (RF) signals from a base transceiver station (BTS), for example, of a conventional cellular network. The DAS is configured to provide multiple coverage areas inside the buildings to support higher capacity and improved RF coverage. Each coverage area includes one or more remote units configured to provide communications services to the client devices within antenna ranges of the remote units.
In this regard, FIG. 1 illustrates distribution of communications services to remote coverage areas 100(1)-100(N) of a WDS 102, such as a distributed antenna system (DAS) for example. These communications services can include cellular services, wireless services, such as radio frequency identification (RFID) tracking, Wireless Fidelity (Wi-Fi), local area network (LAN), wireless LAN (WLAN), worldwide interoperability for microwave access (WiMAX), wide-band code-division multiple access (WCDMA), long-term evolution (LTE), and combinations thereof, as examples. The remote coverage areas 100(1)-100(N) may be remotely located. In this regard, the remote coverage areas 100(1)-100(N) are created by and centered on remote units 104(1)-104(N) (e.g., remote antenna units) connected to a central unit 106 (e.g., a head-end controller, a head-end unit, or a head-end equipment). The central unit 106 may be communicatively coupled to a signal source 108, for example, a base transceiver station (BTS) or a baseband unit (BBU). In this regard, the central unit 106 receives downlink communications signals 110D from the signal source 108 to be distributed to the remote units 104(1)-104(N). The remote units 104(1)-104(N) are configured to receive the downlink communications signals 110D from the central unit 106 over a communications medium 112 to be distributed to the respective remote coverage areas 100(1)-100(N) of the remote units 104(1)-104(N). Each of the remote units 104(1)-104(N) may include an RF transmitter/receiver and a respective antenna 114(1)-114(N) operably connected to the RF transmitter/receiver to wirelessly distribute the communications services to client devices 116 within the respective remote coverage areas 100(1)-100(N). The remote units 104(1)-104(N) are also configured to receive uplink communications signals 110U from the client devices 116 in the respective remote coverage areas 100(1)-100(N) to be distributed to the signal source 108.
It may be important to determine the location of client devices 116 within the WDS 102. For example, many context-aware and location-aware wireless services, such as enhanced 911 (E911) services, rely on accurately detecting the locations of wireless communications devices. A satellite-based location detection system, such as global positioning system (GPS) in the United States, may be unreliable in indoor environments served by the WDS 102 due to the inherent inability of a satellite signal to penetrate obstacles like building walls. Although it may be possible to determine general locations of the client devices 116 based on a signal source (e.g., base station) in a conventional cellular network, it remains challenging for signal sources to pinpoint the locations of the client devices within a WDS, such as WDS 102 in FIG. 1, with a higher degree of accuracy. The location of the client device 116 may be determined within in the WDS 102 based on identify the location of the remote unit 104(1)-104(N) with which the client device 116 is communicating. However, since the uplink communications signals 110U from the remote units 104(1)-104(N) are combined in the central unit 106 before being distributed to the signal source 102, the particular remote unit 104 with which the client devices 116 are communicating cannot be determined.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.